Pump and overflow valve assembly

ABSTRACT

A pump and overflow valve assembly for a fluid pumping system includes a feed pump disposed in a feed pump housing, a return line in communication with the feed pump, an overflow valve disposed in the return line, the valve including a valve body and a valve housing being disposed in the feed pump housing. A spring is disposed between the valve housing and the valve body, and ajoining member is fixed to the valve body and projects outwardly from the valve housing. An adapter is mounted on the feed pump housing and a position switch is rotatably mounted on the adapter and provided with a control surface. Feed pump controlling means are disposed in the adapter and are responsive to selective rotation of the position switch to control operation of the overflow valve and the pump.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This is a continuation-in-part of U.S. patent application Ser.No. 09/826,086, filed Apr. 4, 2001, titled DEVICE FOR ACTUATING ANOVERFLOW VALVE naming Leopold Von Keudell as Inventor, and the entirecontents of which are hereby incorporated by reference. This applicationclaims priority through Ser. No. 09/826,086 to German application 200 08051.2, filed May 4, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to fluid pumping systems, and moreparticularly to a pump and overflow valve assembly, including means foractuating the overflow valve, in particular an overflow valveincorporated in a return line of feed pump. The overflow valve comprisesa valve housing and a valve body, the valve housing being disposed in afixed position in a housing of the feed pump. A compression spring isarranged between the valve housing and the valve body of the overflowvalve, and a joining piece is attached to the valve body and projectsfrom the valve housing. The joining piece is in communication with aposition switch for controlling the feed pump. The position switch isconnected to the joining piece by an adapter mounted in the housing ofthe feed pump.

[0004] 2. Description of the Prior Art

[0005] When feed pumps, in particular diaphragm pumps, are taken intooperation, the fluid should be held in the feed lines of the feed pumpwithout pressure so that the feed pump can start up without feed outputin starting mode. For this purpose, it is necessary that some of thefluid which is going to be pumped by the feed pump be pumped out ofreturn lines after the feed pump has been switched off, with thisevacuation pumping lasting until the feed pressure has been reduced.Consequently, an overflow valve is provided in the return line, by meansof which the excess pressure line is to be opened both in the event ofexcess pressure during operation of the feed pump and when the pump isswitched off and on, such that there is no feed pressure in the feedline.

[0006] Such a device is described in U.S. Pat. No. 4,928,722,incorporated herein by reference, in which a position switch is providedwith a circumferential cam track which acts axially on a switchingbutton of the control switch for the feed pump. This means theelectrical power switch of the feed pump is actuated by rotation of theposition switch. The overflow valve is moved axially at the same time bythe rotation of the position switch. This axial movement of the overflowvalve occurs because the position switch possesses an internal cam trackby means of which an axial movement is induced when the position switchis rotated. The valve body of the overflow valve and its joining pieceare connected to the position switch.

[0007] With this device, it has been proven to be a disadvantage thatthe control system for the electrical power to the motor of the feedpump cannot be reliably actuated because the overflow valve must be heldin an open or a closed position by the position switch at the same timeas the electrical power switch of the motor has to be held ON by theposition switch. The fact that the position switch has to be transferredinto different variable axial positions means that the cam track of thecontrol switch of the motor has to satisfy exacting requirements.Accordingly, the position switch is expensive to manufacture.

[0008] Also, achieving a seal between the housing of the feed pump andthe position switch involves considerable difficulties because the axialmovement of the control switch prevents the use of a reliable seal, suchas an o-ring seal.

[0009] Furthermore, separating the mechanical axial adjustment mechanismof the overflow valve from the electrical power control of the feed pumpis not a technically elegant solution because the spatial separation andthe axial actuation of the control switch for the motor place greatdemands on the design and configuration of the position switch. Thismeans that considerable time has to be expended when changing theoverflow valve, and also that the operating personnel have to cope withmore exacting demands in order to be able to assemble and dismantlethese components.

[0010] In feed pumps of the prior art, the position switch whichactuates the overflow valve from outside is arranged in the housing ofthe pump separately from the electrical switch which controls the pumpmotor. The position switch not only switches the overflow valve but alsothe electric power for the feed pump. Frequently, however, the overflowvalve is arranged in the housing in such a way that the forces formoving the overflow valve have to be absorbed by the position switch orits housing.

SUMMARY OF THE INVENTION

[0011] Accordingly, the purpose of the present invention is to provide apump and overflow valve assembly including means for actuating the valvein such a way that both the axial adjustment of the overflow valve andthe actuation of the electrical control of the feed pump are undertakenusing a common housing, and wherein procedures for assembling anddismantling the components of the device can be carried out quickly andeasily.

[0012] In accordance with the present invention, this task isaccomplished in that electrical, pneumatic, hydraulic and/or mechanicalcomponents for controlling the feed pump are arranged inside an adapter,and in that these components can be actuated by the position switchusing a control surface extending circumferentially around the positionswitch.

[0013] Torque for axial movement of the valve body is transmittedbetween the position switch and the overflow valve by means of alocating hole disposed in the end of the joining piece assigned to theposition switch. A pin is locked in the position switch and extendsperpendicularly to the longitudinal axis of the joining piece andprojects through the locating hole in the joining piece.

[0014] Due to the fact that at least two control surfaces are installedin the position switch and run at an angle in the circumferentialdirection of the position switch, and that cams corresponding to thecontrol surfaces of the position switch are disposed on the adapter, itis assured that the overflow valve can be moved to various positions bythe position switch in relation to the axial direction of the overflowvalve, which means that mechanical connection between the positionswitch and the joining piece of the overflow valve enables the requiredoperating mode of the overflow valve to be selected or set. At the sametime, the position switch also controls the electric switch arranged inthe adapter, which means the rotation of the position switch can be usedfor setting the operating mode of the feed pump in relation to theposition of the overflow valve.

[0015] There is an oval or polygonal accommodation opening in thehousing of the feed pump in order to absorb the torque present in theadapter and the position switch and to lock the adapter in place toprevent it from rotating, so that the torque which occurs is directlytransmitted into and absorbed by the housing of the feed pump.

[0016] In the arrangement of the adapter on the housing of the feed pumpin accordance with the present invention, it is an advantage that theoverflow valve is arranged without play and is not in contact with theadapter. As a result, there is no force transmission between theoverflow valve and the adapter. Instead, this process occurs directlywithin the housing of the feed pump, because the valve housing isscrewed into the housing of the feed pump. The position switch onlytransmits the axial forces of the spring onto the adapter.

[0017] A configuration of this type significantly facilitates assemblyand dismantling of the adapter, the overflow valve, and the positionswitch, for example, in comparison to the design according to the priorart, because the individual components can be removed separately ortogether from the housing of the feed pump.

[0018] The electrical switch arranged in the adapter is needed forcontrolling the feed pump and is not affected when the adapted isremoved, because the electrical circuit elements are mounted in a fixedposition in the adapter and are only connected to the pump in thehousing of the feed pump by means of an electrical control cable. Thisensures it is a quick and simple matter to dismantle or assemble theindividual components, namely the adapter, the overflow and positionswitch together with the electric switch fitted in the adapter.

[0019] In summary, with the above objects in view, a feature of thepresent invention is the provision of a pump and overflow valve assemblyfor a fluid pumping system, the assembly comprising a feed pump disposedin a feed pump housing, a return line in communication with the feedpump, an overflow valve disposed in the return line, the valvecomprising a valve body and a valve housing, the valve housing beingdisposed in the feed pump housing. A spring is disposed between thevalve housing and the valve body and a joining member is fixed to thevalve body and projects outwardly from the valve housing. An adapter ismounted on the feed pump housing and a position switch is rotatablymounted on the adapter and provided with control surfaces. Feed pumpcontrolling means are disposed in the adapter and are responsive toselective rotation and positioning of the position switch to controloperation of the overflow valve.

[0020] The above and other features of the invention, including variousnovel details of construction and combination parts, will now be moreparticularly described with reference to the accompanying drawings andpointed out in the claims. It will be understood that the particulardevice embodying the invention is shown by way of illustration only andnot as a limitation of the invention. The principles and features ofthis invention may be employed in various and numerous embodimentswithout departing from the scope of the invention.

[0021] Reference is made to the accompanying drawings in which is shownan illustrative embodiment of the invention, from which its novelfeatures and advantages will be apparent.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a perspective view of a paint spraying apparatus usefulin the practice of the present invention.

[0023]FIG. 2 is an enlarged, fragmentary, partially cutaway view of aportion of the apparatus shown in FIG. 1, to illustrate the pump andmotor associated with the present invention.

[0024]FIG. 3a is a section view of a pump and overflow valve assembly,including an overflow valve, joining piece, adapter, position switch,control switch and a portion of a feed pump illustrative of anembodiment of the invention, with the position switch in a firstposition and the control switch in a first or OFF position.

[0025]FIG. 3b is a section view similar to that of FIG. 3a, except withthe position switch in a second position, and the control switch in asecond or ON position.

[0026]FIG. 3c is a section view similar to that of FIG. 3b, except withthe position switch in a third position with the control switch in thesecond, ON, position.

[0027]FIG. 4 is a section view taken along line IV-IV of FIG. 3b showingthe position switch and the control switch.

[0028]FIG. 5 is a section view taken along line V-V of FIG. 3b showingthe position switch.

[0029]FIG. 6 is a diagrammatic view of the operation of the positionswitch.

[0030]FIG. 7 is a fragmentary section view taken along line VII-VII ofFIG. 3b with parts removed showing mating portions of an adapter andfeed pump housing.

[0031]FIG. 8 is an exploded perspective view of the pump and overflowvalve assembly.

[0032]FIG. 9 is a circuit diagram for the apparatus shown in FIG. 1,useful in the practice of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0033] Referring to the Figures, most particularly to FIG. 1, a paintspraying apparatus 50 useful in the practice of the present inventionmay be seen. Apparatus 50 may include a paint hopper 52 or other meansfor delivering paint to a pump and motor assembly 54 which willpressurize the paint and deliver it to a spray gun 56 via a highpressure hose 58. Apparatus 50 utilizes an electric motor connected to apower cord set 60.

[0034] Referring now to FIG. 2, the pump and motor assembly 54 includesan electric motor 62 which powers a feed pump 2 having a diaphragm 64.Pump 2 also includes a piston 66 driven by an eccentric 68, which isrotated via drive belt assembly 70 connected to motor 62.

[0035]FIGS. 3a-3 c and FIG. 8 show an assembly or device 1, including anoverflow valve 5 arranged in a return line 4 of the feed pump 2. Theoverflow valve 5 comprises a two-part valve housing 6 and valve body 7(FIG. 3a) which is shown in an open position so that the return line 4is clear. The two-part valve housing 6 is preferably screwed into ahousing 3 of the feed pump 2. Both parts 6 a, 6 b of the valve housing 6are connected together in the form of a screw connection 6 c. Acompression spring 8 is arranged between the valve housing 6 and thevalve body 7 to ensure normal valve control in the operating mode of thefeed pump 2. Consequently, if valve 7 is closed, (as shown in FIG. 3c)and there is increased fluid pressure in the return line 4 acting on thesurface 7 a of the overflow valve 5 facing away from the valve body 7,then the overflow valve 5 is opened irrespective of its setting and theexcess pressure in the normal feed circuit of the feed pump 2 isdissipated because the overflow value 5 is open.

[0036] An adapter 9 (FIGS. 3a -3 c and FIG. 8) is supported against thehousing 3 of the feed pump 2 and is provided with a through hole oraperture 10 in which is disposed a portion of a position switch 12having therein a bore 22 for accommodating a joining piece 11 fitted tothe valve body 7. As a result, the joining piece 11 projects through theadapter 9, beyond the open end of the hole 10 (FIG. 3a).

[0037] A distal end portion 11 a of the joining piece 11 is held in theposition switch 12. A mechanical connection between the position switch12 and the joining piece 11 includes a locating hole 13 provided in thearea of the distal end portion 11 a of the joining piece 11 and a pin 14projecting through the locating hole 13 of the joining piece 11perpendicular to the longitudinal axis of the joining piece 11. A distalend 14 a of the pin 14 is held in a blind hole 15 in the position switch12. In addition, the position switch blind hole 15 is provided with athreaded portion 17 which receives a head end portion 14 b of the pin 14in assembled condition. An external thread 18 is provided on the headend portion 14 b of the pin 14 so that the pin 14 is screwed into theposition switch 12 and is therefore firmly locked into it.

[0038] Referring to FIGS. 3a-3 c and 4, it will be seen that anelectrical switch 16 features a nose or mechanical contact 20spring-biased by a coil spring 19 into engagement with a connectorportion 37 of a control surface 38. Electrical wires 36 are connected toelectrical contacts (not shown, but within switch 16) to selectivelyprovide electrical power from a power source (not shown) to a motor 62for pump 2 fluidly connected to the return line 4. The movable switchcontact 20 is maintained in continuous engagement with the connectingportion 37. The electrical switch 16 is operated between the OFF and ONelectrical conditions when the connecting portion 37 of position switch12 is manually rotated. It is to be understood that nose 20 acts like acam follower and is operated or moved between OFF and ON positions inresponse to the cam-like surface of connecting portion 37 and controlsurface 38. Switch 16 is OFF when contact 20 is engaged with flatcontrol surface 38, and switch 16 is ON when contact 20 is engaged witha cylindrical part of the connecting portion 37.

[0039] In FIGS. 3a-3 c there are illustrated three operating positionsI, II, III of the overflow valve 5 and the pump motor 62. In FIG. 3a,the position switch 12 is disposed in a shut-off position (I), whereinthe valve 5 is open and the pump motor 62 receives no energy. At thistime nose 20 of electrical switch 16 is allowed to move to a firstposition by contact with connector surface 38 to maintain the switch 16in an OFF condition. In FIG. 3b, the position switch 12 is in the secondposition (II) in which the flat control surface 38 of the connector 37moves out of contact with the switch contact 20, urging nose 20 ofswitch 16 to move to actuate switch 16 to an ON electrical condition andposition. It to be understood that in the second position (II) of theposition switch 12, the pump motor 62 receives electrical energy andtherefore operates, but the valve 5 is still open and the pumped fluidgoes into the return line 4. As will be described hereinafter,electrical power to motor 62 may be controlled by switch 16 actingthrough a relay or motor starter. The second position (II) correspondsto a bypass or priming condition for the pump 2. In FIG. 3c, theposition switch 12 is in the third position (III) in which thecylindrical part of connector portion 37 is in contact with the switch16 in the same condition as shown in FIG. 3b. The electrical switch 16has a pair of internal contacts closed in this condition, correspondingto an electrical ON condition, providing electrical power to the pumpmotor, causing the pump to be in operation. In this instance, theoverflow valve 5 is closed and the fluid is transported through anoperational line or hose 58 under high pressure. The cylindrical part ofconnector portion 37 stays engaged with the electrical contact 20 in thepositions II and III, such that the pump motor receives operating powerduring both positions II and III.

[0040] Referring to FIG. 6, it will be seen that the position switch 12includes the previously described bore 22 for receiving the joiningpiece 11. The reference characters I, II and III illustrate the threepositions of the position switch 12 when rotated. The level betweenpositions I and II is equal (i.e., unchanged). The level of position IIIis removed from the level of positions I and II. The rise of the slopebetween positions II and III defines an axial distance which is equal tothe distance x through which the valve can be moved (FIGS. 3a-3 c).

[0041] Accordingly, when the position switch 12 is moved from position Ito position II the pump motor 62 starts, as noted above, but the valve 5remains open, so the pumped fluid simply circulates through the returnline 4.

[0042] When the position switch 12 is moved to position III, the motor62 and pump 2 continue in operation and the valve 5 closes, blocking thereturn line 4 and causing the pumped fluid, under pressure, to flowthrough the operational line 58 to spray gun 56.

[0043] In accordance with FIGS. 4 and 5, the position switch 12, whenthe assembled condition possesses four ribs 31 which incline in thedirection of the adapter 9. Each rib 31 forms a control surface 32running at an angle. The ribs 31 are evenly spaced circumferentially ofthe position switch 12 and are arranged symmetrically in relation to thetransverse axis of the position switch 12. This means both halves of theposition switch are configured identically to one another, so that theposition switch 12 can be connected to the adapter 9 in two positions.

[0044] Two cams 33 (FIGS. 3a-3 c) on the adapter 9 extend towards theposition switch 12, and the control surfaces 32 of the ribs 31 are heldagainst the cams 33. The inclined control surfaces 32, acting inconjunction with the rotation of the position switch 12, ensure that thejoining piece 11 connected to the position switch 12 effects axialmovement.

[0045] When the position switch 12 is turned, in addition to controllingelectrical power to the pump motor 62, the position switch 12 alsoaffects the operation of the overflow valve 5. In moving between thefirst position (I) (FIGS. 3a and 6) and the second position (II) (FIGS.3b and 6), the distance between the valve and its shut-off position isnot changed because the level of the position switch 12 is not changed.However, when the position switch 12 is turned to the third position(III) (FIGS. 3c and 6), relative axial movement between the cams 33 andthe control surfaces 32 of the ribs 31 allow movement of the overflowvalve a distance sufficient to effect closure of the return line 4 (FIG.3c).

[0046] As can be seen in FIGS. 3a and 5, the free end 11 a of thejoining piece 11 is provided with a non circular cross section 28 whichis configured and acts in conjunction with the bore 22 of the positionswitch 12 in such a way that the joining piece 11 can be introduced intothe locating hole 10 of the position switch 12, with the result that thelocating hole 13 of the joining piece 11 can be aligned with the blindhole 15 for the pin 14, locking the joining piece 11 within the positionswitch 12. Non-circular cross section 28 may be one or more flatsurfaces formed on the free end 11 a of the joining piece 11. As may beseen most clearly in FIGS. 3a -3 c and FIG. 5, an extension region 21 ofbore 22 is preferably congruently shaped in cross section and formed toclosely interfit with the non circular cross section of free end 11 a.The pin 14 can be pushed through the locating hole 13 after the joiningpiece 11 has been introduced into the position switch 12.

[0047] Furthermore, the non-circular cross section 28 guarantees thatthe overflow valve 5 can be attached in a defined position in theposition switch 12, so that the position switch 12, together with theelectric switch 16 inside the adapter 9, permit both the feed pump 2 andthe overflow valve 5 to be controlled.

[0048]FIGS. 7 and 8 show an oval-shaped accommodation opening 23 forretaining the adapter 9, the opening 23 being disposed in the housing 3of the feed pump 2 (FIGS. 3b and 8). The adapter 9 has a mating surfaceor joining element 24 congruent to opening 23. Element 24 is insertedinto the opening 23 to form a non-rotating connection. The ovalconfiguration of the accommodation opening 23 means the adapter 9 cannotrotate with respect to the housing 3.

[0049] As can be seen most clearly in FIGS. 3a and 8, the adapter 9 ismade up of two housing components 34, 35 which can be fixed to oneanother and secured to the housing 3 of the feed pump 2 by means offastening bolts 27 which pass through the adapter 9. The adapter 9 maybe attached to the housing 3 of the feed pump 2 irrespective of thelocking mechanisms for both housing components 34 and 35. Furthermore,centering pins (not shown) can be provided on the adapter 9 extendingtowards the housing 3, so that the adapter can be attached to thehousing 3 in a predetermined position.

[0050] The electrical switch 16 for the feed pump 2 is provided withinthe two housing components 34 and 35. The electrical switch 16 isconnected to control motor 62 of the feed pump 2 by means of theelectrical wires 36. As such, the position switch 12 controls both theelectrical switch 16 provided in the adapter 9 and the position of theoverflow valve 5.

[0051] The overflow valve 5 is assembled in such a way that a part ofthe valve housing 6 is screwed into the housing 3 of the feed pump 2.The overflow valve 5 is inserted into the outwardly open housing part ofthe valve housing 6 and the compression spring 8 is inserted. The secondhousing part of the valve housing 6 is screwed onto the first part ofthe valve housing 6, so that the overflow valve 5 is firmly locked intothe housing 3 of the feed pump 2 by means of the valve housing 6. Inthis arrangement, the joining piece 11 of the overflow valve 5 projectsout of the housing 3 of the feed pump 2. The through-hole 10 in theadapter 9 accommodates the joining piece 11 of the overflow valve 5. Thefastening bolts 27 are used for bolting the two components of theadapter 9 onto the housing 3 of the feed pump 2.

[0052] The joining piece 11 projects from the adapter 9 and the positionswitch 12 is connected onto the joining piece 11. The non-circular crosssection 28 (FIG. 7) on the distal end 11 a of the joining piece 11permits the position switch 12 to be connected to it in a definedfashion. In order to attach the position switch 12 onto the joiningpiece 11, the pin 14 is pushed into the blind hole 15 provided for itwithin the position switch 12 and projects through the joining piece 11by way of the locating hole 13. The threads 18 provided on the pin 14lock the pin 14 into the position switch 12. Furthermore, the positionswitch 12 includes the connecting portion 37 projecting towards theadapter 9, with the connector portion 37 having a flat or cam surface 38on its side which serves as the control surface 38. The correspondingcongruent non-circular surface 21 in the hole 22 definitively determinesa position of the position switch 12 with respect to the joining piece11.

[0053] Referring now to FIG. 9, a circuit diagram 72 for the paintspraying apparatus 50 may be seen. Switch 16 is shown in the OFFcondition in diagram 72. When switch 16 is moved from the positionshown, connection is made between leads 74 and 76 of electrical wires36, providing power to a coil 78 of a load relay 80. Load relay 80 hascontacts 82 controlled by coil 78, such that when coil 78 is powered,contacts 82 provide “mains” power from an electrical mains plug 84 tomotor 62. It is to be understood that when mains power is present, asecond relay 86 will be powered, closing its related contacts, tocomplete the circuit between lead 76 and coil 78.

[0054] It will be understood that many additional changes in thedetails, materials, steps and arrangements of parts, which have beenherein described and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principlesand scope of the invention as expressed in the appended claims.

What is claimed is:
 1. A pump and overflow valve assembly for a fluidpumping system, the assembly comprising: a feed pump disposed in a feedpump housing; a return line in communication with said feed pump; anoverflow valve disposed in said return line, said overflow valvecomprising a valve body and a valve housing, at least part of said valvehousing being disposed in the feed pump housing; a spring disposedbetween said valve housing and said valve body for biasing said valvebody toward a closed position; an adapter mounted on the feed pumphousing; ajoining member fixed to said valve body and projectingoutwardly from said valve housing; a rotatable position switch mountedon said adapter and provided with a circumferential contact surface; andfeed pump controlling means disposed in said adapter and responsive toselected rotation and positioning of said position switch to controloperation of said overflow valve and said pump.
 2. The assembly inaccordance with claim 1, wherein said joining piece is provided with alocating hole in an end portion of said joining piece disposed in theposition switch, and a pin is locked into said position switch andextends perpendicularly to a longitudinal axis of the joining piece, andprojects through the locating hole in said joining piece.
 3. Theassembly in accordance with claim 2, wherein a free end of the pin isheld in a blind hole disposed in said position switch, a head piece ofthe pin being screwed into an internal thread provided in the positionswitch blind hole.
 4. The assembly in accordance with claim 2 whereinsaid position switch, when rotated, causes the valve body to be movedaxially.
 5. The assembly in accordance with claim 1 wherein saidposition switch is provided with at least two control surfaces, andwherein said adapter is provided with cams having surfaces complementaryto the control surfaces of the position switch.
 6. The assembly inaccordance with claim 1 wherein said adapter and said position switchare removable separately and together from the housing of the feed pump.7. The assembly in accordance with claim 1 wherein an accommodationopening is provided in the housing of the feed pump to retain saidadapter in place and prevent said adapter from rotating.
 8. The assemblyin accordance with claim 7, wherein said adapter is provided with anexternal contour complementary to the shape of the accommodationopening.
 9. The assembly in accordance with claim 1 wherein said adaptercomprises a plurality of housing components.
 10. The assembly inaccordance with claim 9, wherein a first of said housing components isprovided with a projection defining a through-hole provided for passagetherethrough of said overflow valve, the projection projecting towards asecond of said housing components when said housing components areassembled, and said second housing component is provided with a recessadapted to receive an external contour of the projection.
 11. Theassembly in accordance with claim 9, wherein said housing components areattached to each other.
 12. The assembly in accordance with claim 1wherein a cross section of a free end portion of said joining member isof a shape corresponding to a blind hole in said position switch. 13.The assembly in accordance with claim 12, wherein the cross sectionalshape in the blind hole of said position switch is configured such thatsaid joining member is held in a predetermined position in said positionswitch.
 14. The assembly in accordance with claim 12, wherein aconnector portion of said position switch is provided with a controlsurface and wherein the connector portion is insertable into saidadapter, and wherein when said position switch is assembled, the controlsurface is in contact with a mating surface provided in said adapter.